Edible spreads such as margarine are often used for shallow frying purposes. Margarine, like butter, contains around 80% fat and 20% of a water phase. In recent years, consumer concern with health has led to the increased use of reduced fat spreads comprising around 60% fat and 40% of an aqueous phase. This doubling or in some cases further increase in water content leads to "spattering" problems when such spreads are used for shallow frying.
Spattering problems can be minor in that some hot fat is ejected from the frying pan causing inconvenience and soiling of work-surfaces or spattering problems can be major, in that "catastrophic spattering events" occur leading to ejection of large quantities of hot fat. Spattering problems may also occur with deep frying fats. Spattering is a long-standing technical problem upon which a great deal of effort has been expended. Many contradictory results have been obtained, for example smooth enamelled pans give more spattering than would be expected and relatively cool pans give more spattering than would be expected. In the face of these results it has proved difficult to predict spattering behaviour of spreads.
It is convenient to differentiate between two types of spattering under experimental conditions. So-called "primary" spattering occurs when a portion of spread is heated to drive off the water-phase. This heating step is a necessary preliminary to shallow frying with water containing spreads such as margarine and 60% fat spreads. "Secondary" spattering occurs when water is added to hot fat. Such addition is difficult to avoid when food articles are placed in fat for deep or shallow frying. It is important that both forms of spattering are reduced.
It is known to add anti-spattering agents to spreads and other frying fats so as to reduce the spattering tendency. Anti-spattering agents include, nitrogen, salt, calcium chloride or phosphates, and emulsifiers such as egg yolk and lecithin. Antagonistic effects have been noted between anti-spattering agents such that the combination of two known anti-spattering agents may increase spattering above the expected level. It has also been found that while some anti-spattering agents are excellent in reducing primary spattering they actually increase the extent of secondary spattering.